I've heard of Argos, they seem great but are pricey/have quite long lead times.
I'm not unapposed to drilling a hole to reduce stress concentrations, every other bike I've owned has been built that way. I'll see what I think after getting a quote from Argos.
The cheap fix (Argos aint cheap) would be to drill a hole where the crack stops, to make a sort of upside down keyhole.